Details
| Original language | English |
|---|---|
| Pages (from-to) | 28-36 |
| Number of pages | 9 |
| Journal | Applied Clay Science |
| Volume | 145 |
| Early online date | 29 May 2017 |
| Publication status | Published - 1 Sept 2017 |
Abstract
Clay amendments are used widely in the horticultural industry in peat-based substrates, as they have the capability to improve the potassium (K) buffering capacity. The K adsorption and desorption behavior of different clays was characterized here to develop criteria for identification of clays suitable for substrate amendment and to evaluate their significance for plant K uptake. K adsorption of saprolitic, bentonitic and relocated clays from the Westerwald area, Germany, was characterized with adsorption isotherms for calculating the maximum adsorption capacity for K. The K desorption was quantified in a percolation experiment using 0.01 M CaCl2 as extractant. The influence of a varying K adsorption capacity of the clays on the K availability to plants was investigated in a growth experiment. The availability of K in substrates was determined by 0.01 M CaCl2 (CAT), Ca-acetate-lactate and NH4 acetate. Different cultivation practices were simulated by varying the start of K topdressing: “immediate,” “delayed” and “no” K topdressing. A higher K adsorption capacity of the clays amended resulted in a lower K concentration in the pore solution of clay-amended peat-based substrates, while the CAT extractable K concentration was the same. It also resulted in an enhanced plant growth and higher K concentrations in the shoot without K topdressing. The uptake of K by plants exceeded the amount of exchangeable K in some peat-clay blends where no K was fertilized. The amount of K released from the clays in the plant experiments was in the same magnitude as the maximal desorbable K determined in the percolation experiment and was highly dependent on the mineralogical composition in the order: smectitic > illitic, kaolinitic clay. The K released from the clays contributed significantly to the supply of K to plants.
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geology
- Earth and Planetary Sciences(all)
- Geochemistry and Petrology
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In: Applied Clay Science, Vol. 145, 01.09.2017, p. 28-36.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Potassium adsorption and release properties of clays in peat-based horticultural substrates for increasing the cultivation safety of plants
AU - Binner, I.
AU - Dultz, Stefan
AU - Schellhorn, M.
AU - Schenk, Manfred K.
N1 - Publisher Copyright: © 2017 Elsevier B.V. Copyright: Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2017/9/1
Y1 - 2017/9/1
N2 - Clay amendments are used widely in the horticultural industry in peat-based substrates, as they have the capability to improve the potassium (K) buffering capacity. The K adsorption and desorption behavior of different clays was characterized here to develop criteria for identification of clays suitable for substrate amendment and to evaluate their significance for plant K uptake. K adsorption of saprolitic, bentonitic and relocated clays from the Westerwald area, Germany, was characterized with adsorption isotherms for calculating the maximum adsorption capacity for K. The K desorption was quantified in a percolation experiment using 0.01 M CaCl2 as extractant. The influence of a varying K adsorption capacity of the clays on the K availability to plants was investigated in a growth experiment. The availability of K in substrates was determined by 0.01 M CaCl2 (CAT), Ca-acetate-lactate and NH4 acetate. Different cultivation practices were simulated by varying the start of K topdressing: “immediate,” “delayed” and “no” K topdressing. A higher K adsorption capacity of the clays amended resulted in a lower K concentration in the pore solution of clay-amended peat-based substrates, while the CAT extractable K concentration was the same. It also resulted in an enhanced plant growth and higher K concentrations in the shoot without K topdressing. The uptake of K by plants exceeded the amount of exchangeable K in some peat-clay blends where no K was fertilized. The amount of K released from the clays in the plant experiments was in the same magnitude as the maximal desorbable K determined in the percolation experiment and was highly dependent on the mineralogical composition in the order: smectitic > illitic, kaolinitic clay. The K released from the clays contributed significantly to the supply of K to plants.
AB - Clay amendments are used widely in the horticultural industry in peat-based substrates, as they have the capability to improve the potassium (K) buffering capacity. The K adsorption and desorption behavior of different clays was characterized here to develop criteria for identification of clays suitable for substrate amendment and to evaluate their significance for plant K uptake. K adsorption of saprolitic, bentonitic and relocated clays from the Westerwald area, Germany, was characterized with adsorption isotherms for calculating the maximum adsorption capacity for K. The K desorption was quantified in a percolation experiment using 0.01 M CaCl2 as extractant. The influence of a varying K adsorption capacity of the clays on the K availability to plants was investigated in a growth experiment. The availability of K in substrates was determined by 0.01 M CaCl2 (CAT), Ca-acetate-lactate and NH4 acetate. Different cultivation practices were simulated by varying the start of K topdressing: “immediate,” “delayed” and “no” K topdressing. A higher K adsorption capacity of the clays amended resulted in a lower K concentration in the pore solution of clay-amended peat-based substrates, while the CAT extractable K concentration was the same. It also resulted in an enhanced plant growth and higher K concentrations in the shoot without K topdressing. The uptake of K by plants exceeded the amount of exchangeable K in some peat-clay blends where no K was fertilized. The amount of K released from the clays in the plant experiments was in the same magnitude as the maximal desorbable K determined in the percolation experiment and was highly dependent on the mineralogical composition in the order: smectitic > illitic, kaolinitic clay. The K released from the clays contributed significantly to the supply of K to plants.
UR - http://www.scopus.com/inward/record.url?scp=85019661214&partnerID=8YFLogxK
U2 - 10.1016/j.clay.2017.05.013
DO - 10.1016/j.clay.2017.05.013
M3 - Article
AN - SCOPUS:85019661214
VL - 145
SP - 28
EP - 36
JO - Applied Clay Science
JF - Applied Clay Science
SN - 0169-1317
ER -